Lawn mower



July 4, 1950 Y B. T. GROBOWSKI ET AL 2,513,309

LAWN MOWER Filed Jan. 24, 1946 5 Sheets-Sheet l l8 i I 34 3b IO If w J m INVENTORS +5 5 BznnyTGrobowskn.

F155. 2 BY John PArndi'.

ATTORNEYS July 4, 1950 B. T. GROBOWSKI ET AL 2,513,309

LAWN MOWER Filed Jan. 24, 1946 3 Sheets-Sheet 2 INVENTORS John P. Arndi.

BY M, w M

ATTORNEYS Benny T Grobowski.

y 1950 B. T. GROBOWSKI ET AL 7 2,513,309

LAWN MOWER Filed Jan. 24, 1946 5 Sheets-Sheet 5 INVENTORS Bznny T Grobowski. John P Arndf.

ATTORNEYS Patented July 4, 1950 UNITED STATES PATENT OFFICE LAWN MOWER Benny T. Grobowski, Newark, and John P. Arndt, Malta, Ohio, assignors to The E. T. Rugg Com pany, Newark, Ohio, a corporation of Ohio Application January 24, 1946, Serial No. 643,062 g 3 Claims. (01. 56 -249) Our invention relates to a lawn mower. It has to do, more particularly, with a lawn mower of improved rugged construction which is of such a nature that the various necessary adjustments for proper operation are facilitated.

In the prior art, various and sundry lawn mower structures have been provided. One disadvantage of prior art law mower structures is that they are of such a nature that relative distortion or springing of the supporting frame, the cutting reel, and the cutting bar often occurs upon striking objects in the grass, such as small stones and twigs. Springing of any of these parts obviously prevents proper operation of the mowerand is generally impossible to correct properly. Another disadvantage of prior art structures resides in the fact that they usually include complicated structures for adjusting the mower to vary the depth ofcu't and for positioning the cutter bar relative to the cutter reel. Furthermore, these adjustments are difficult to make properly and accurately with such structures. Also with prior art structures, various operating parts are not sufficiently protected from clogging by grass and dirt.

One of the objects of our invention is to pro vide a lawn mower of an extremely rugged construction which is of such a nature that distortion or springing ofvarious parts, which tend to resultfrom striking objects such as stones or twigs, will be precluded.

Another object of our invention is to provide a lawn mower wherein the cutting reel and cooperating cutter bar are both supported by the same rugged frame unit so that there will be no danger of relative displacement or distortion during operation of the mower.

Another object of our invention is to provide a lawnmower which is provided with a simple yet effective structure for quickly and easily adjusting the mower to vary the depth of cut.

Another object ofour invention is to provide a simple, effective and easily operable structure in a lawn mower for adjusting the cutte'r'bar and the cutting reel accurately relative to each other.

Still another object of our invention is to provide a lawn mower which is so constructed that the various operating parts thereof are completely and effectively protected from clogging by grass or dirt.

Various other objects will be apparent hereinafter.

In its preferred form, we provide alawn mower in which extreme rigidity is accomplished by providing a transversely extending yoke or frame unit which supports both the cutting reel and the cutter bar in rigid association with each other. This yoke further serves to rigidly connect together, insofar as lateral movement is concerned, the side plates of the mower which, in turn, carry the supporting wheels. However, the side plates are pivotally adjustable relative to the yoke. The side plates also carry the transversely extending ground-engaging roller at a point behind the reel. The side plates have associated therewith gear arrangements for simultaneously adjusting the wheels and the ground roller vertically relative to the axis of the cutting reel in order to vary the depth of cut of the mower. The cutter bar is provided with a knifeedge which may be adjusted quickly and easily relative to the cutting reel to provide the proper cutting action.

The preferred embodiment of our invention is illustrated in the accompanying drawings wherein similar characters of reference designate corresponding parts and wherein Figure l is a vertical sectional View taken through a mower constructed according to my invention and taken substantially along [-1 of Figure 2.

Figure 2 is a horizontal sectional View taken substantially along line 2-2 of Figure 1.

Figure 3 is a vertical sectional view taken substantially along line 3-3 of Figure 2.

Figure 4 is a detail, in section, illustrating the adjustable mounting for the cutter bar knife on the cutter bar.

Figure 5 is anend view of the cutter bar and knife showing one of the knife adjusting screws.

"Figure 6 is a view, partly in section, taken substantially along line 6-6 of Figure 5.

Figure 7 is a top perspective view, partly broken away, of the end of the cutter bar and knife.

Figure 8 is an interior perspective View, partly broken away, of one end of the mower.

Figure 9 is a sectional view taken substantially along line 99 of Figure 8.

Figure 10 is a view mainly in elevation but partly in section illustrating the yoke carrying a modified cutter bar structure.

Figure 11 is an end view of the structure shown in Fig. 10.

With reference to the drawings, we have illustrated our lawn mower as comprising a one-piece frame unit I which may be termed a yoke. This yoke I (Figure 8) is rigidly cast in one piece and, in its preferred form, consists of a top bar 2 and a bottom cutter bar 3 which is adapted to support a knife. The bars 2 and 3 extend transyersely substantially the full width of the mower 2) which contain the ball bearing units Ifithat rotatably support the shaft. The outer endsiof the shaft 9 have driving pinions l I loosely carried thereby. Between each pinion and -the sha ft within the bearing cup 5,"=there is;'provideda clutch unit l2 (Figures 1 and 2') which'ds'of a type in common use. This'clutch willwserv 'to rotate the shaft 9 when the pinion is rotated in one direction, but will not drive the-shaft upon rotation of the pinion in the opposite directiont .3 l'.\:' j a C k Each of the pinions is driven by means of an internal ring gear -13 (Figure 2)-zp'rovided"orr the interior ofaeach' supporting and :driving "wheel 4'..- rEach=-wheela| 4 'incIudsLa hub\ 5'whichicarri'es a roller bearing l3 thatzsurround'sxthe'wheellaxle 1-1.: It will be apparentcthat: each-(Wheel? I 4 -is hollow and the pinion extends thereinto, and the axisaof the pinion: andshaft.9-is disposed eccentric relative .:to:- the 'wheel= axle ll. '1 The innerside 'of each wheel is sub'stantially closed by-.a wheel'plate |8=that=has:an outwardly extend ing peripheral-flange |9:-1.th-at .extends into a'n angularigroove formed in-the inner surface ofthe rimof the ivheel. The:fiange I9 and groove 2.9 cooperate to substantially seal the: wheel and prevent dirtand grass from interfering: with the operation' -of the meshing pinion-l l' andgear l3. The wheel=is maintained 'onlthe axle l'l by means of a nut 2| whichiis protected by a removable hub-cap 22. The-pini0nx1i and shaft 9=extend through an opening- -in -plate 18: which is eccentrically located therein while the axle rll extends throughan opening at the center of -the plate- Each wheel axle extends inwardly :through an arcuate slot 23 formed adjacenttlie' forward end (Figures l; 2 and-8) 'of-a'vertically disposed side plate 24 whichris of substantiallylova'liorm having its highenzpor'tion forwardxrThisaplate 24 isprovided'- with an inwardly extending flange 25 around its. entire peripheryu-r Thearcuateslot 23 is of considerable length and is disposed-concentrio 'withthe axis of the shaft-ll. The' axle extends'through this slot and its inner end is welded, asuindicated at -26 -.in Figure 2, to' the outer surface-of aidouble gear segment 21 which is disposed within. the side plate 24. This double gearsegment Z'I is'i-ntheform of anarm which is rotatably supported on the bearing 'cup 5 and which has a gear seg-ment 28 -atthe'upper end thereof and a gearsegment zil at the lower end thereof, as shown in Figures land-"8; The segmentsi28 and 29 are 'also concentric with the haft Qff. if .z. 1:

Each of the segments 28 engages a pinion 39 which is .keyed on :the end ofa transversely extending bumper rod 3|. This rod 3| is m'ainly of hexagonal crosssection' but is--provided'with a reduced rounded-bearing portion 3-2- at' each end thereofwhichfits into a bearing opening formed in the 'side 'plate fl adjace'nt'the forward end thereof. Within the plate 24, there" is provided a cover pla't'e '3-3 -which will protect the mechanism within the plate '24 from'clogging with dirt or grass. The plate 33 is provided with a central opening 50 that it may be slipped over the bearing cup 5 and is further provided with an outwardly directed peripheral flange 34 which lies closely adjacent the flange 25 on the side plate 24 to provide an effective seal. The rod 3| passes through a circular opening 35 formed in the plate 33. It will be apparent that rotation of rod3| will simultaneously rotateboth of the pinions-38.

It will be noted best from Figures 2 and 9 that in assembling the structure at each side of the mower, the plate 33 is first positioned by slipping it over the outer end of the cup 5 and moving it until it rests -against the ledge 36 adjacent the inner -s'ide'of the-cup. The double segment 21 is then' similarly'slipped over the cup 5 until it is positioned -upon 'the annular shoulder 31 upon which it will rotate. The plate 24 is then slipped over the cup 5 with the axle ll of the wheel passing through the slot 23. This plate will engage the ohterisurface of the shoulder 31; "'The'wlieel plate: I 8* iSIthen" positioned on the cup and the nut/ 38 Sis :threadedror'r the'outer -end 'of the cup inrorder toiclampthe platte -l8 and the plat 24 tightly and non rotatably'to the cup 5- which, as previously: ex'plaindgis carried by the "yoke I. The'imai'n part of'the wheel-will then-be applied 'toitheiaxleillrs 1 1;" '1' '1 o The segment 29 on the lower end of member 21 meshesa'witha-pinion 39' (Figures 1 and -8)'; This pinioni39' is rotatably carriedby a stud 49 which isrjourn'aled in the side plate24-adjace1it the rear end-thereof. The pinion-39 meshes with a' vertically'sl'idable rackllr -The rack 4| is" provided with a vertical slot' 42 into-which apair .of guid'e bolt": units 43 extend: These units 4 3are' carried by? thersideplate-M and I are 'so' arranged'that' th rack d! willhe tilted f0rwardly,'-a's shown'in Figure 19- At least'onle of these bolt units'43 provided with a'clamping'nut'44outsidethe plate 24': socthatthe' rack 'ca'n' be clafnped and'held' in any! adjusted position." Thisj consequently; will lock'the tpinion 39;" the double segment '21, the pinioni3ll, and the bumper rod" 3 l'in "a fixed 'po'si tion. -'--Each of the racks 4| carries on its lower end ant-inwardly projectingroller trunnion 45. Each trunnione'xtends into a ball bearing unit 46 which is mountedin the end of'a transverseiy extendin ground roller '41 which may-"be "the -"usual wood roller. Thus, upon vertical -movementof racks 4 I the roller 41 will =lc'e' moved'Wertically since the roller is carriedb'y the racks The lowerbar- 3of' the' yoke I adjustably sup ports the knife '48 for cooperation withtlie cutting ireel 6. This"structureis'iIIustratedbest in Figures 4 t0 '7. The knife 48' is" of-fiat'cro'sssection' but-has an upstanding-shoulder 49 along its for-ward edge which-"serves to provide a shearing edge? The knife 48 issiipported on the lower surface of thebar '3 by meansof'a, plurality of longitu'dinallyspaced screws 50'wh ich are threaded'into thelower surface'of' bar 3 and which extend through slots 5| extending transversely of the'knife as. It will beno'ted' th'at'the shoul der' 49 is ahead of thebar '3'. "Eachend off the knife' ifl is provided witha' reduced extension 52 which is provided with a pairof upstanding spaced lugs 53. "The extension 52 is "disposed within the bifurcated lower end of the "arm-4 whichextends belowthebarfi; adjusting screw 54 is threaded transversely through'the bifurcated lower end "of 'arm'4 and is provided witha reduced'midportion-which the lugs 53 i straddle. The screws SUmaintain'the knife 48 against the bar 3 but will not prevent relative movement of these members. I i By operating the screw 54 at each end of the yoke, the knife 48 maybe moved forwardly or rearwardly, as indi cated in Figure 4, to properly adjust the shearing edge relative to the cutting reel '6.

With the structure described above, extreme rigidity will be acquired due to the provision of the integral yoke I. This yoke not only supports the cutting reel and the cutter bar so that they will always be in proper position relative to each other, but it also rigidly connects the side plates 24 to each other. structure results.

In using the mower, the various parts are assembled in the manner previously described. The yoke member I is adjusted about the axis of the shaft 9 until the cutter bar 3 is properly positioned relative to the cutting reel 6. The knife 48 will usually be located in a position slightly behind the axis of the cutting reel or, in other words, the lower portion of the yoke I will be swung rearwardly behind the axis of the cutting reel. When the yoke is properly located, as indicated, the nuts 38 are tightened firmly to clamp the yoke in a fixed position.

The next adjustment is to adjust the knife 48 forwardly or rearwardly on the bar 3 to obtain a fine adjustment of the shearing edge thereof relative to the knives of the cutting reel. This may be quickly and easily accomplished merely by operating the screws 54.

In order to adjust the lawn mower to obtain the proper depth of cut, it is merely necessary to release the clamping nut 44, associated with rack 4|, and rotate the bumper rod 3| with a. wrench. This will simultaneously rotate both of the pinions 30. Rotation of the pinions 30 will swing the double segment member 21 around the bearing cup 5, or in other words, around the axis of the cutting reel shaft 9. Consequently, this will move the wheel axles I1 through the slots 23 or about the axis of the shaft 9. Swinging of the member 21 causes the lower segment 29 to rotate the pinion 39 which, in turn, will slide the rack 4| vertically. Thus, it will be apparent that the rack will be moved vertically in the same direction in which the wheel axles I! are moved.

With this adjustment, upon rotation of the bumper rod 3!, the two wheels 14 are simultaneously moved vertically relative to the yoke l and the cutting reel carried thereby and also, at the same time, the ground-engaging roller 4! is moved vertically relative thereto in the same direction. Thus, this will locate the integral yoke l, and the various parts carried thereby, at a different height relative to the ground-engaging wheels I4 and the ground-engaging roller 41 and, consequently, will vary the depth of cut. Furthermore, this adjustment will be accomplished without disturbing the relationship of the knife 48 and the cutting reel 6. After this adjustment, the nut 44 may be tightened to lock the various parts in adjusted positions.

The handle structure for pushing the lawn mower may be attached in the manner illustrated in Figures 1 and 8. Thus, the lower arms 55 of the handle structure may pass through slots 56, formed in the flanges 25 of the side plates 24 and may be pivoted, as at 51, to the vertical surfaces of the side plates.

In Figure 10, we illustrate an arrangement of a modified form of yoke structure and cutter bar Thus, an extremely rigid frame structure. In this instance, the yoke'la ismade substantially the same as'before with the exception that it is not providedwith an integral lower transverse bar 3. The cutter bar 48a is made in one piece and isof'diiferent cross-sectional form having an integral upstanding flange 49a on its forward edge which has a sharp knife edge for cooperating with the reel knives. Each end of the cutter bar is provided with an upstandin lug 52a. which carries trunnions 521) that are rotatably mounted in bearing lugs 41) formed on the lower ends of the arms 4a of the yoke. The arms 411 on their inner surfaces also are provided with inwardly extending lugs 40 through which a pair of screws 54a are threaded downwardly at converging angles. These screws engage inclined surfaces 53a formed on the upper ends of the lugs 52a.

It will be apparent thatby merely adjusting the screws 54a, the cutter bar 48a will be swung about the axes of the trunnions 52b and will, consequently, provide for adjustment of the flange 49a relative to the cutting reel carried by the yoke la.

It will be apparent from the above description that we have provided a lawn mower structure in which distortion and misalignment of parts will be precluded even upon striking hard objects in the grass, due to the rigidity accomplished by the use of the rigid yoke structure. Furthermore, it will be apparent that the depth of out can be varied readily with little trouble. Also, the cutter blade knife can be accurately and quickly adjusted relative to the reel knives. All operating parts, including both the adjusting mechanism within the side plates and the driving mechanism within the wheels, is completely protected from dirt and grass.

Having thus described our invention, what We claim is:

1. A mower comprising a transversely extending rigid yoke having bearing housings at each end thereof, a cutting reel having its shaft rotatably mounted in bearings in said housings, a cutter bar carried on the lower side of said yoke in association with said cutting reel and parallel to the axis thereof, side plates adjustably connected to each end of said yoke at the axis of the cutting reel, ground-engaging wheels associated with said side plates, said wheels being supported by axles which project through arcuate slots formed in said side plates, said slots being concentric with the axis of the cutting reel, a double gear segment disposed within each side plate and carrying one of said axles, said gear segment being mounted for rotation about the axis of said cutting reel, a bumper bar extending transversely and having pinions keyed thereto for engaging one pair of said segments, a rack carried by each of said side plates for vertical movement, and a pinion rotatably carried by the side plate and engaging said rack, the pinions carried by the side plates being rotated by the other pair of said segments.

2. A structure according to claim 1 wherein a knife is adjustably carried by said cutter bar so that it may be adjusted toward and from the cutting reel.

3. A mower structure according to claim 1 including a knife disposed beneath said cutter bar and being connected thereto by pin and slot connections for adjustment toward and from the cutting reel, and screws carried at each end of said bar and engaging said knife for adjustment 7- thereof-transversely relative to :said bai and.to-

Number UNITED STATES PATENTS ward and'awa-y-from the cuttingr eel. m I Date BENNY T. G 2,061 )O3 Nelson Nov. 17, 1936 JOHN P; ARNDT. I 5 v FOREIGN PATENTS v q Number Country Date REFERENCES CITED 5,095 Great Britain 1888 The following references are of'record in the 18,347 Great Britain 1889 file of this patent: r 113,287 Australia June 9, 1941 Great Britain Nov. 22, 1943 

